Method of manufacturing, combustibles for explosives.



' UNITED STATES PATENT OFFICE.

O$CAB BERGER CQBLSON, F MANSBO, AVESTA, SWEDEN, ASSIGNOR TO OSCARFBEDBIK CAELSON, OF STOCKHOLM, SWEDEN.

mi'rnon or MANUFACTURING,COMBUSTIBLES non EXPLOSIVES.

No Drawing.

To all whom it'mag] concern:

Be it known that I, OSCAR Braces CARL- soiv, a subject of the King ofSweden, and resident of Mz'tnsbo, Avesta, in the Kingdom of Sweden, haveinvented certain new and useful Improvements in the Method ofManufacturing Combustibles for Explosives, of which the following is aspecification.

,In a previous U. -S. patent application, Ser. -No.-'543534, I haveindicated a method (if-manufacturing a combustible f or explosives, thesaid method being characterized thereby that resin or nitrated resin isallowed to re-act at an increased temperature for a considerable timeonnitrated organic substances. Hereby a slowly continuing chemicalreaction takes place, which results inthe formation of substances havingquite different physical and chemical properties fromthose 6f thestarting material. The present invention especially refers to'therelation of said substances to nitrating acid or acid mixture, thisrelation being of the greatest interest from theoretical as well as frompractical point of view for the manufacturing of explosives. The saidsub stances can namely be nitrated further by means of even ratherfeeble nitric acid (sp. aogravity for instance 1.25-1.40), even if forinstance the resin was wholly nitrated, and

if the nitro compound used had been pro- -duccd by means of thestrongest nitrating egent known, for instance a mixture of -nitric acidand sulfuric acid. Thus, by re- "oiprocalchemical .re-action oftwowholly nitrated substances, each of which having -been produced bymeans of the strongest .practical nitrating agents new substances 4o areformed which are comparatively easy to nitrate further even by using acom- .paratively feeble nitrating agent. 'It has, :however, not beenfound necessary to exe icute-t-his subsequent nitrating process after'having performed the reaction between resin or nitro compounds of thesame on one hand I and organic nitro compounds on the other, but it hason the contrary been found'possilble to execute this subsequentnitrating proce'ss at'thesameftime asfthe chemical re- Specification ofLetters Patent.

action betweenresin or nitrated ,products of the same and organic nitrocompounds. From techincal point of view it is evidently a considerableadvantage 'to attain the desired effect by a single process instead oftwo, but on occasion-it may, however, be 'ad- Patented Dec. 22, 1914.

Application filed June 15, 1911. Serial No. 633,357.

vantageous to produce the combustible by one process and to'subsequentlynitrate the same by another. When using for instance nitratedresin-which is porous it generally ought to be best to soak the samewith a required quantity of nitric acid, and then permit the nitrocompound em loyed toreact on the same for a time su cient foraccomplishing the-reaction: This subsequent nitrating reaction accountsfor the fact that, introducing conib'ustibles according to the abovementioned'process invented by me, a perfectly neutral product isobtained, even if washing of the nitrated starting materials is omitted.The product thus obtained is very suitable for the production of strongexplosives, particularly as they have been found "to be very'stable. Forinstance, when executing Abelstest no reaction takes place after heatingto 80 cent. for half an hour.

When the product is to be used in explosives it is of the greatestimportance that by the subsequent nitrating process practically noraising of the fusing point and no alteration of the viscosity'arecaused, the product being in this respect quite as suitable for theproduction of plastic explosives as the combustible indicated in thespecification of my above mentioned previous U. S. patent application.

WVhen starting from highly nitrated organic substances as for instancehighly ni trated resin, and when driving the 'subse-. quent nitratingprocess sutficiently far the product obtained may be used as anexplosive without any addition ,whate'ver of oxidizing salt, but formost purposes such an explosive is too expensive. In such cases 'oneemploys cheaper, lower nitrated bodies and mixes the product with asuitable quantity of oxidizing'salt. On account of the viscous characterof the product the explosive produced in this way will remain plastic,even if the mixture contains as much as 8O185 per cent. of acrystalline, oxidizing 'sa t.

From executed experiments it seems to result that the new nitro groupsarisen from the subsequent nitratingprocess are bound to the part of theproduct issuing from theresin or nitrated resin. Though it seems to bepossible to drive the subsequent nitrating yet higher the total amountof nitrogen has, by the working process generally used by me,corresponded to a mixture of nitrated resinwith about 7.5 N. and thenitro body employed. (As has been stated above it is no ordinarymixture, but the mixed parts are believed to have chemically reactedupon each other). This rather constantamount of nitrogen found bycalculation seems to indicate that only the group arising from the resinand not the nitro body employed takes part in the subsequent mtratingreaction, If subsequent nitrating of the nitro body contained in themixture should take place it is not possible to understand wherefore sohigh an amount of nitrogen can not be obtained, if one starts from forinstance mononitro-benzene or from trinitro-benzene.

From the above mentioned fact it seems to be evident that it has beenpossible to nitrate the resin further after it has reacted on or duringits reaction with a nitrated organic substance. The difiiculty in nitrating resin is to prevent the oxidation which occurs very easily. Thisis Why the products of oxidation of resin have been known for a longtime, while it has been considered to be impossible to nitrate resin. InBailsteins handbook of organic chemistry it is stated that when treatingresin with nitric acid. the result will only be products of oxidationfree from nitrogen, while the products of nitrat-ing seem to be unknownto him. However, if some precautions are taken resin can be nitrated sothat a total amountof nitrogen of a little more than 5% is obtained. Ifone tries to drive the nitrating reaction further oxidation willimmediately take place. After or during the reaction with other nitrocompounds the resin is, however, as will be clear from the foregoing,more resistant to oxidation and, therefore, it binds a higher amount ofnitrogen than by the ordinary nitrating process.

The reaction between resin, nitrated or not, and a nitrated organicbodv, is as follows: In resin, as Well as in most terpenes, doublebindings can easily be shown. for instance, a'nitrated organic body withthe formula shall react with resin, the constitution of gravity during 8which, whether it is nitrated or not, can be expressed with theformulal-R1 -R: ii

the reaction is gxpressed as follows:

If the nitrogen were bound in the organic nitrated body in any otherway, analogous formula: can be advanced.

From the above example it will be evident that the reaction on which thepresent method is based is independent of whether the resin'is nitratedor not. The case is, of, course, such that in unnitrated resin there maybe more double bindings than in the nitrated resin, and that some doublebinding is unbound by the nitrating process. How this case in fact is,is not easyto decide; however, it can be proved that also inthe'niti'ated resin, principally in the form of nitratedabietinice-acid, there remains at least some {probably two) of theoriginal double, bind ngs. The formula of reaction \vilL prove that theonly condition forthe possibility of executing the reaction is thepresence of at least one double binding in the resinous body.

- Finally, some examples may be cited:

1. 3 kg. of trinitrotoluene containing 18.5% of nitrogen were allowed toreact at a temperature of (3., upon 1 kg. of nitrated resin with 5.2% ofnitrogen, in the presence of 0.3 liter of nitric acid of 1.35 sp. hours.A product contain ing about 16% of nitrogen was obtained. This productitself may be used as an-explosive. a

2. 37.5 kg. of nitrated resin containing 3.5% of nitrogen were inthe-presence of 10.3 liters of nitric acid of 1.35 sp. gravity allowedto react upon 62.5 kg. of nitrated toluene containing 12% of nitrogen ata temperature of 70 C. After 15 hours a product containing 10.5% ofnitrogen was obtained. Hereby 98% of the nitrogen of the nitric acidemployed were recovered in the product. If 21 kg. of this product aremixed with 79 kg. of ammonium perchlorate a plastic explosive withsuperior qualities is obtained.

The specific temperatures, times and specific gravities in the foregoingexamples are not absolutely required to execigse the process, but aregiven as advantageous working examples.

The following examples are given to show first, that other nitrocompounds than aromatic ones could be used, as, for instance, nitro'starch, and hence the invention is not to be limited to aromaticcompounds, and, second, to give. an example with common (unm'tra'ted)resin.

' 3. 37.5 kg. of nitrated resin with 3.5%

of nitrogen are allowed to react, in the presence of 120 1 of nitric'acid specific gravity-1.32 at 75, with 58 kg. of nitrated toluol with12% of nitrogen and 4.5 kg.- of nitrocellulose withl1-}% N. One obtainsa 'productwith 10.4% N. of which 21.5 parts givesa plastic explosive.

' 60 kg. of nitrated toluene containing 12% of nitrogen and with 4.5 kg.of'nitrocellu 5. 40- kg. of nitrated containing 3.5% of nitrogen wereallowed to react with lose containing 11.5% of nitrogen at a moderatelyincreased temperature.- The pro'dnot obtained was further heated to'75C.

together with 120 litres of nitric acid having a specific v of reaction0 tained contained 10.4% of 85 avity of 1.32. The product nitrogen andgives, in the ratio of 20.5; 79.5

a plastic explosive.

.From the above examples Nos. 3 and '5,

it-will be clear that the same result is obtained whether the nitratingagent is present during the reaction between the nitrated resin and thenitrated organic-body or if it is added after such reaction. For

pi'actical reasons, however, the method according to example .3 ought tobe preferred. In the foregoing the nitrating of the product of reactionhas been referred to as a-subsequnt nitrating operation even in theCopies of this patent ma lie-obtained m case that the nitrating agent ispresent durmg the principal reaction. This is due to the fact thatin'all cases the reaction takes place in such a-. ma nnler that thecombustible,

is first formed'andthen nitrated, even if the nitrating agent is present'during'. the reaction between resin-or nitrated resin' and Organic nitio con pounds'g,

What I claim is; 1. In a method 0* preducing combustibles forexplosives, allowing a resinous. suba stance to react upon anflorganicnitro compound at a temperature above the ordina'r'y atmospherictemperatureand for a time sufficient to complete the reaction andmitrating the product of reaction.

2. In a method of producing combustibles for explosives, allowingnitrated resin to 'react upon an organic nitro compound at a temperatureabove the ordinary atmospheric temperature and-fora time sufiicient tocomplete the reaction and nitrating "the product of reaction.

3. In a method of producing comhi stibles for explosives, allowingnitrated resin to react uppn an organic Intro-compound at'a temperatureabove the ordinary atmospheric temperature and for a time sufiicient toa nitratingagent for nitrating the product of reaction.

4. In a method of producing combustibles for explosives, allowingnitrated resin to react uponan organic nitro compound at a temperatureabove the ordinary atmospheric complete the reaction in the presence oftemperature and for a time sufiicient to 7 complete the reaction,nitrating the product of reaction and adding a solid oxidizing salt tothe product obtained.

In witness whereof, I have hereunto signed my name in the presence oftwo subscribing witnesses.- I

OSCAR BIRGER CABLSON, Witnesses:

Axnr. EHRNER, Hnnwrc Mnmmmn.

flvei'cents each, by addressing the "Commissioner of Iatents,

washin ton, n; c."

